You will learn
- Say that the ones digit tells how many single things.
- Read the ones digit in a number.
- Show a number of ones with objects.
- Explain that 10 ones make a ten.
Version 0.2 · expanded edition · built from cited public sources Content is based on the official frameworks and sources listed under Sources and standards. No official endorsement is claimed. Written in the style of common primary school assessments. No exam result is promised.
Student lesson
- Ones are single things.
- The ones digit is on the right.
- In 36 the ones digit is 6.
- Ten ones make one ten.
Words to know
Single things. The digit on the right.
One symbol in a number.
Where a digit sits in a number.
How much a digit is worth.
1. Discover: single seeds
Here are 6 single seeds. They are not in bundles. We call single things ones. How many ones do you see?
2. Understand: understanding ones
The digit on the right of a number is the ones digit. In 23, the ones digit is 3. It shows 3 ones.
In 40, the ones digit is 0. There are no ones.
You can have up to 9 ones. When you have 10 ones, you make a ten and write 0 in the ones place.
Idea 1: Ones are single things
5 beans are 5 ones. Each bean is one single thing.
Idea 2: The ones digit
The ones digit is the digit on the right. In 57 it is 7. In 30 it is 0, because there are no single ones.
Why the right side? The right place always holds the single things.
Idea 3: Ten ones make a ten
7 ones and 5 more ones make 12 ones. Ten of them make 1 ten, and 2 ones are left. So 12 ones is 1 ten and 2 ones.
3. Worked examples
Example 1 (I show you): Ones digit in 57
What is the ones digit in 57?
- Look at the digit on the right.
- It is 7.
Answer: The ones digit is 7.
Example 2 (We do it together): Ones digit in 30
What is the ones digit in 30?
- Look at the digit on the right.
- It is 0. There are no single ones.
Answer: The ones digit is 0.
Example 3 (You try): 7 ones and 5 more ones
You have 7 ones and get 5 more ones. What do they make?
Show the steps and answer
- 7 + 5 = 12 ones.
- Ten ones make 1 ten.
- 2 ones are left.
Answer: 1 ten and 2 ones, which is 12.
Did you know?
The ones place is the first place in every number. As we move left we reach tens, hundreds and thousands.
Why this matters
Ones are the smallest part of a number. Knowing the ones digit helps with counting and adding.
4. Explore: count the ones
You need 15 counters.
- Put 7 counters in a row. Write the ones digit: 7.
- Add 3 more. How many ones now?
- Regroup the 10 ones into a ten. Write the number.
- Say how many tens and ones.
Think about it: what did you notice?
7 + 3 = 10 ones = 1 ten and 0 ones.
5. Practise
Say it in a sentence
Use these starters when you talk about the lesson. Say them out loud.
- The ones digit of ___ is ___.
- ___ has ___ ones.
- Ten ones make ___.
- I find the ones digit on the ___.
Guided practice
Question 1. What is the ones digit in 28?
8.
Question 2. Ones in 40?
0 ones.
Question 3. How many ones make a ten?
10.
Independent practice
Level 1: Start
- Ones digit in 57?
- Ones digit in 30?
- Draw 5 ones.
- What happens when you have 10 ones?
- Write a number with 6 ones.
Level 2: Grow
- What is the ones digit in 82?
- How many ones are in 40?
- Write a number with 9 ones.
Level 3: Stretch
- Mia has 8 ones and gets 4 more ones. What do the ones make?
- Which two numbers have the same ones digit: 23, 45, 63?
- Tom says the ones digit of 50 is 5. What is his mistake?
Answers are in the answer key below. Try first, then check.
6. Apply: everyday mathematics
A box holds 10 pencils. Mia has 14 pencils. How many full boxes and how many ones?
Show a sample answer
1 box and 4 ones.
Another one. A shop has 10 single pencils. How can it pack them?
Show a sample answer
Ten ones make one ten. It can pack them as one pack of ten.
7. Common mistakes
Fix: The ones digit shows only single things. The tens digit shows groups of ten.
Fix: The ones digit is the digit on the right.
Fix: A zero in the ones place means no single ones. 30 has 0 ones.
8. Lesson summary and revision card
- I can say that the ones digit tells how many single things.
- I can read the ones digit in a number.
- I can show a number of ones with objects.
- I can explain that 10 ones make a ten.
9. Check and master
Answer all 14 questions. You will see feedback after each one.
Your result appears here after you answer every question.
10. Key takeaways
- The right-hand digit is the ones digit.
- You can have 0 to 9 ones in a place.
- Ten ones make a ten.
11. Next lesson
Next lesson: Understanding tens. Keep going with the next idea in this course.
Exam practice
These questions are written in the style of common school and international primary assessments. Try them on your own, without looking back. Then check your answers in the marking guide. The marks are shown in brackets.
- What is the ones digit in 64? [1 mark]
- How many ones are in 50? [1 mark]
- Write a number that has 7 ones. [1 mark]
- Sam has 6 ones and gets 7 more ones. What do the ones make? Explain. [3 marks]
- Ali says the ones digit of 38 is 3. Is he right? Explain. [2 marks]
Total: 8 marks.
Marking guide and model answers
- 4 [1]
- 0 [1]
- Any number ending in 7 [1]
- 13 ones [1]; 1 ten [1] and 3 ones [1]
- No [1]. The ones digit is on the right and it is 8 [1].
Score guide: 7 to 8 = secure. 5 to 6 = nearly there, revise the parts you missed. Under 5 = work through the lesson again with a grown-up.
Printable worksheet
- Ones digit in 49?
- Ones digit in 60?
- Write a number with 3 ones.
- 10 ones = __ ten
- How many ones in 5?
- What is the ones digit in 91?
- How many ones are in 20?
- Draw 4 ones.
- Write a number with 2 ones.
- How many ones make a ten?
Homework
Look at three two-digit numbers at home (a calendar, a book page). Say the ones digit of each and show it with small objects.
Answer key and marking scheme
| Question | Expected response | Marks |
|---|---|---|
| Ones digit in 49? | 9 | 2 |
| Ones digit in 60? | 0 | 2 |
| Write a number with 3 ones. | 13, 23, 33 … (any ends in 3) | 2 |
| 10 ones = __ ten | 1 | 2 |
| How many ones in 5? | 5 | 2 |
| Total | 10 |
Practice answers: Worksheet: 1 9; 2 0; 3 13, 23, 33 … (any ends in 3); 4 1; 5 5.
Quiz answers: 1 A, 2 B, 3 C, 4 A, 5 B, 6 A, 7 B, 8 C, 9 A, 10 B, 11 C, 12 A, Challenge 1 C, Challenge 2 C.
Extra worksheet answers (items 6 onward): 6 1; 7 0; 8 Four dots or beans; 9 Any number ending in 2; 10 10.
Independent practice answers. Level 1: 1 7; 2 0; 3 five dots or five beans; 4 they make 1 ten; 5 any number ending in 6, such as 16 or 36. Level 2: 1 2; 2 0; 3 Any number ending in 9, such as 19 or 49. Level 3: 1 12 ones, which is 1 ten and 2 ones; 2 23 and 63; 3 The ones digit is on the right, and it is 0. The 5 is the tens digit..
Mastery and remediation
| Objective | Bronze (Developing) | Silver (Proficient) | Gold (Advanced) |
|---|---|---|---|
| O1 Say that the ones digit tells how many single things | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O2 Read the ones digit in a number | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O3 Show a number of ones with objects | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O4 Explain that 10 ones make a ten | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
Courseversity badge thresholds (overall quiz score): Gold = 90–100%; Silver = 80–89.9%; Bronze = 70–79.9%. A badge is never a full record of progress.
If a learner struggles
- Find the misconception: Thinking the ones digit shows the biggest part of the number. The ones digit shows only single things. The tens digit shows groups of ten.
- Explain another way: use real objects first, then pictures.
- Show a simpler example: Count single counters up to 9, then group 10 to make a ten.
- Guided practice: work through one example together and let the learner try the next one.
- Reassess: use the quiz again or the worksheet.
- Move on when the learner shows Silver-level evidence independently.
For parents and guardians
In this lesson your child learns what the ones digit means. You do not need to be good at mathematics to help.
- Use beans: show 7 ones, add 5 more and make a ten.
- Ask: what is the ones digit of 25? Of 40?
- Point out numbers on buildings or buses and name the ones digit.
- Ask “how do you know?” after each answer, and listen.
- Praise effort, not only right answers. Mistakes are how we learn.
- Ten to fifteen minutes a day is better than one long session.
Teacher package
1–5. Objectives, prerequisites, materials, preparation, duration
Lesson objectives. Learners will: say that the ones digit tells how many single things; read the ones digit in a number; show a number of ones with objects; explain that 10 ones make a ten.
Prerequisite knowledge. Lesson 1: grouping into tens.
Materials. Counters (stones, seeds or bottle tops), paper, pencils, board or chalkboard. Low-resource options: use stones, seeds, sticks, bottle tops or drawings in the sand or on the board instead of printed materials.
Preparation. Gather the counters and draw the example pictures on the board before the lesson.
Suggested duration. 45–60 minutes. It can be split into two shorter sessions.
6–9. Teaching procedure, explanation notes, guided and independent activities
Introduction (5 min). Start with the Discover situation and let learners suggest ideas before you teach.
Explanation (10 min). Teach the Understand section with real objects first, then pictures, then symbols and words.
Guided activity (10 min). You need 15 counters. Learners follow the Explore steps in pairs.
Independent activity (10 min). Learners complete the independent practice and the worksheet.
Assessment and reflection (5 min). Ask each learner to say one thing they learned and how they know it.
Key questions. Where is the ones digit? What does a zero in the ones place mean? How many ones make a ten?
Teacher explanation notes. Use the concrete, pictorial, abstract order: real objects first, then pictures, then symbols and words. Return to real objects whenever a learner needs support.
10–12. Differentiation, formative assessment, common misconceptions
Support. Use real objects and work with a partner; say each step aloud together. Extension. Ask learners to make up their own example and explain it to a partner.
Formative assessment. Listen to learner explanations, ask “how do you know?”, and check the independent work.
Misconceptions. Thinking the ones digit shows the biggest part of the number. The ones digit shows only single things. The tens digit shows groups of ten.
13–15. Assessment questions, answer keys, marking scheme
Use the quiz and worksheet on this page. The 8-mark exam practice scheme, the 10-mark scheme and all answers are in the answer sections above. Re-check every answer and the marking scheme before publication.
16–19. Remediation, enrichment, homework, teacher reflection
Remediation. Count single counters up to 9, then group 10 to make a ten. Enrichment. Invite learners to find or create three more examples at home or in the classroom and explain them. Homework. See above.
Teacher reflection. After teaching, record: which concepts learners understood; which misconceptions occurred; which activities worked; which learners need more practice; and what to improve next time.
Sources and standards
This lesson is based on the sources below, and no official endorsement is claimed. Reference starting points named in the Courseversity standard: Common Core State Standards for Mathematics, Cambridge Primary and the IB Primary Years Programme. Where a standard code is named, it points to the official framework.
Official standards for this topic area. Common Core State Standards for Mathematics (official site): Grade 1 » Number & Operations in Base Ten. These pages list the standards that cover this topic area; read them alongside the lesson.
Research used to shape this lesson. Common Core 1.NBT.B.2 (place value); Cambridge Primary Mathematics Stage 1. These sources informed the lesson.